Electrode positioning device



Nov. 1, 1938.

c. D. TOWNE 2,135,296

ELECTRODE POS ITIONING DEVICE Filed Oct. 21, 1936 2 SheetsSheet 1 IN VENTOR.

New. 1, 1938 D. TOWNE 2,135,295

ELECTRODE POSITIONING DEVICE Filed Oct. 1, 1936 2 Sheets-Sheet 2 INVENTOR.

Zvwl 67mm Patented Nov. 1, 1938 UNITED STATES,

PATENT OFFICE 6 Claims.

This invention aims to provide a device capable of indicating a desirable position for a pair of electrode ends the use of which is to ignite combustible fluids whether liquids or gases, when an electric spark is produced between the ends of the electrodes, for example, as in the case of an oil burner, gas refrigerator or any similar apparatus when combustible fluids are to be ignited.

Records have shown, over a long period, that electrode ends which produce the electric spark must be so set that when combustible fluids to be ignited, are admitted in the proximity of the electrodes, these electrodes must be in proper position relative to the angle of spray of the fluids to be ignited, to prevent a failure of ignition. There are many ways to assemble the electrodes in relation to the fluids to be ignited, and in the event proper setting is not made, failure of the apparatus results, which always causes incon- 20 venience and sometimes causes severe damage to the apparatus such as explosions of major importance. History of oil burner installations tells us of bad fires caused by the failure of igniting the oil as admitted to the combustion chamber where it is to burn in suspension. The same is true when other fluids whether liquids or gases are to be ignited.

It has been found that if the electrode points are in the path of the fluids, due to the differential 30 of temperatures between electrodes and fluids, a

carbon deposit forms on the electrodes of sufcient size and shape to short circuit the electrode ends; thereby causing failure of ignition. It has also been found if the electrode points are too far 35 out of the spray, failure of ignition results. It has been found that when the electrode ends are set in the same horizontal or vertical position, radio interference is eliminated by such setting.

The width of the gap between the electrodes is 40 very important and this distance must be such that the electric current will jump the gap under the conditions surrounding the electrodes such as air velocity, etc. It was also found that a certain distance must be maintained between the 45 electrodes points and all other metals. It is therefore evident that a device, such as the present invention provides, is a practical addition to the art for the following reasons:

1. Said electrode points must be in proper posi- 5 tion to ignite the fluids.

2. If the electrode ends are in the fluids, a formation of carbon prevents ignition.

3. If electrode points are too far away from the fluids, a failure of ignition results.

4. If electrodes are too close to metal parts of assembly, electric spark is or may be produced other than across the electrode points which would cause failure of ignition.

5. If electrode points are too far apart, an electric spark will not be produced; thereby causing a failure of ignition.

6. If electrode ends are not set in the same horizontal and vertical plane, radio interference will or may result.

7. Failure of ignition for any cause prevents the proper operation of the equipment such as an oil burner, gas refrigerator, gas burner, or any apparatus which depends on electric ignition toignite the fluids for its proper operation.

The device herein shown, for purposes of illustration, is adapted for use in connection with a present-day oil burner of the pressure-atomizing type, wherein the fuel issues in spray formation. It will be understood, however, that my device may be adapted for use with various kinds of fuel and burners.

The invention will be more readily understood by the following description of one embodiment thereof and reference to the accompanying drawings. The scope of this invention, however, will be evident from the appended claims.

In the drawings:

Figure 1 is a plan view of an oil burner assembly showing my novel device positioned thereon for the purpose set forth;

Figure 2 is a side elevationof the device as shown in Figure 1;

Figure 3 is an enlarged longitudinal section on line 3-3 of Figure 1;

Figures 4 and 5 are verticalcross sections on lines 44 and 5 5', respectively, of Figure 3;

Figure 6 is a plan section on line 65 of Fi ure 3;

Figure 7 shows a modified form of device adapted for special use.

Figures 8, 9 and 10 are views of another modified device, free from adjustments, and therefore not universal; and

V Figure 11 is a diagrammatic illustration, on an enlarged scale, of the various desirable electrode settings relative to the fuel exit Figures 12 and 13 are side and front elevations, respectively, of a portion of the device.

Present-day atomizers are designed to produce many different angles of spray, for example, a 30, 45, 60 or 80 degree spray, and my novel device has been designed to accommodate each size by simple adjustment means variable at will by the operator to meet individual conditions.

There have been various devices adapted to adjust the electrodes as to the spark-gap; but, to the best of my knowledge, there is no known device adapted to position the points in desired relationship with the fuel exit. My device accomplishes both settings in one operation.

Numerous tests have shown that the electrodes should be positioned, relative to the spray of fuel, so as not to be in the spray but close enough to it so that the arc of flame will ignite it. It follows that a practical method of setting the points correctly is to establish a. point relative to the atomizer outlet, a given distance above the axis thereof and a given distance away therefrom in a horizontal line. It also follows that one way to obtain a desirable setting of the electrodes,- relative to the atomizer outlet, is to measure from the atomizer itself, or its equivalent; I will presently describe methods by which this may be best accomplished, using the axis of the atomizer outlet and the exit of said outlet as pre-established point from which to measure. The dimensions of an atomizer being known, its support,'or coupling, may be used as a base from which to measure; in this case the coupling may be utilized to support my device during the electrode setting operation. The fact that standard atomizers may vary in lengthmust be guarded against, when this method is used; therefore, I prefer to use each atomizer as a gauge during the setting operation and any variations in the length thereof will be automatically compensated for.

For thesake of clarity of description, only the necessary elements of an oil burner with which the device of this invention directly co-operates have been shown in the drawings, viz., the conventional electrode assembly comprising a supporting member I usually supported'withina tube, (not shown) called the gun', and adapted'to support an oil line in the nature of a pipe 2, the outer end of said pipe being adapted to receive an atomizer, which will be presently referred to. The supporting member is usuallyslotted and provided with clamping screws 3 for holdingthe electrodes 4 in operating position relative to the atomizer, and permitting adjustment thereof with respect to each other and said atomizen- The outer ends, 5, of these electrodes provide a sparkgap adapted to ignite fuel emerging from the atomizer; it is the spacing of ends 5 and their positioning, relative to the atomizer outlet, with which we are concerned.

The pipe 2, comprising the oil line, usually passes through support I and is clamped thereto so there can -be no relative movement therebetween; therefore, when electrodes 4 have been clamped to support I'they are also established relative to pipe 2, and also the atomizer carried thereby. The oil pipe 2 is usually threaded, as shown at 6to receive a threaded couplingl, known to the trade as an atomizer body, into, or onto, which the atomizer is attached, the latter usually being threaded and provided with a shoulder which engages the outer end of coupling 1 when said atomizer is in operating position; hence, this outer end of coupling 1 is pre-established relative to support I and remains in fixed relationship thereto at all times. I

As above stated, the overall length of standard atomizers may vary slightly so to avoid error due to this fact, I prefer to utilize the outer end 7 of coupling 1 as a point from which to measure,

normally occupied by an atomizer. I therefore provide a rotatable shaft 8, which may be threaded, or otherwise adapted for connection with coupling 1, the former being provided with a shoulder 9 to engage the end of said coupling in the same manner as an atomizer. A handle [0 is provided at the opposite end of shaft 8 to facilitate manual rotation thereof when mounting the device.

The shaft 8 is adapted to receive and support a base member II, the outer end of said shaft being of reduced diameter to form a shoulder l2 and receive a compression spring l3 disposed between said shoulder and an adjacent portion of the base member, as shown in Figure 3. An annular groove M in shaft 8 is adapted to receive a stop element l5 normally forced into engagement with said groove by a spring IS, the element I5 being provided with a head I! to permit manual disengagement thereof with the groove l4, whereupon spring I3 will'cause base 'll, and its associated parts, to move away from the electrodes and contact the hub of handle ID as a stop. This permits the ready disengagement of the electrode engaging elements from the properly adjusted electrodes so that the gage can be readily removed from the burner without disturbing their adjustment. I

It will be seen that when stop element l5 engages groove |4 this arrangement establishes base member II at a definite distance from shoulder 9 on shaft 8, and therefore from the outer end of coupling 1 also.

screw l8 to lock base H in a desired position on shaft 8.

A, vertically extended bracket I9 is fixedly mounted on base II and provided with a gauging surface 20 adapted for contact with the-outer end of an atomizer, when the latter is being usedas a gauge; It follows that this'gauging surface 20 is located at a definite and fixed distance from the outer end of coupling 1 when the device is in operable position as shown in Figures 1 and'2. It will also be understoodthat the axis of shaft 8 occupies a position identically the same as .the axis of an atomizer outlet, when the latter is in its normal operating position, thereby establishing a definite and fixed point from which to measure in a vertical direction.

The upper portion of base member I is adapted to receive a slidable plate element 2| and the former may be provided with inturned flange members 22 arranged to engage grooves in the plate 2| as shown in Figure '4. .A compression spring 23 is arranged to urge the plate 2| in the direction towards the electrodes 4 at all times. Fixedly mounted upon plate 2| is a forked'member 24 designed to receive thelthreadedperiphery of an atomizer 25, the edge 26 of said member being engaged by a shoulder 21 on the atomizer, said shoulder being the same which engages the outer end of coupling 1 when said "atomizer is in its normal operating position, but which is now being used as a gauge to position plate 2| relative to the surface 20 on bracket l9. Compression spring 23 serves to hold the atomizer 25 clamped between member 24 and bracket l9 as clearly shown in Figure 2. By'the foregoing arrangement plate 2| may be positioned correctly by individual atomizers.

It has been determined that the spray of fuel emerging from an atomizer is best adapted for ignition purposes at a given distance from the outlet thereof, where the proper mixture of air-with Any variation from this setting may be had, in special cases, by use of a set the spray is in correct ratio to induce rapid ignition of the fuel and it is, therefore, most desirable to position the electrode ends substantially within this area. Referring to Figure 11, I have shown an enlarged outline of an atomizer and a diagrammatic representation of the principle involved in this invention. Let line A-A represent the axis of an atomizer outlet B, and the series of lines radiating therefrom may indicate the various angles of spray above referred to. Lines C, D, E and F may represent the axes of the electrode ends relative to axis A-A; line 0 being associated with a spray angle of 80 degrees; line D with one of 60 degrees; line E with one of 45 degrees, and line F with a spray of 30 degrees. Let line G represent the ends, or points, of the electrodes and it follows that the inter-section of this line with lines C, D, E and F, respectively, indicates the spark-gap position relative to outlet B with respect to each difi'erent angle of spray. Although the foregoing settings have given excellent results it will be understood that I do not limit myself thereto in any way, and Figure 11 is intended merely to illustrate a principle.

Referring now to Figure 3, I prefer to have the slidable plate element 2! extended upwardly, as at 28, from the axis of shaft 8 and inclined at an angle relative thereto, said angle being substantially the same as represented by line G -G in Figure 11. This upwardly extended portion, 28, is adapted to support and guide a movable element 29, shown detached in Figures 12 and 13, operable by a thumb screw 30 toraise or lower said element and set the same according to the angle of spray in use. Scale indications of spray angle may be utilized, as shown, in Figures 2 and '7, which correspond to marks on standard atomizer, as above referred to, for proper positioning of element 29 for its associated atomizer, but, can be adjusted for different settings. A clamping screw 3! is provided to lock element 29 in the desired setting after adjustment thereof.

It will be understood that element 29 is adjustable relative to the axis of shaft 8, which also represents the axis of an atomizer outlet when in operating position, otherwise said element is rigidly associated with plate element 2i. It will be noted that the member H is in a predetermined position with respect to the coupling 7, but the gage should be set with relation to the nozzle. Where the length of the nozzle is constant, this can be done by fixing the part 2! carrying the gage members in the proper position thereon, but where the length of the nozzles may be expected to vary, the positioning of any given nozzle between the plate 59 and the member 24 serves automatically to position the part 2! with its gage elements correctly positioned for that particular nozzle, since the plate 2! and the gage elements are moved back from the no nozzle position of the base H by exactly the length of that nozzle. At that side of element 29 adja cent coupling the former is provided with a pair of laterally adjustable anvil members 32, each having an upstanding gauge member, 33, rigidly attached thereto, the members 32 being movable toward and away from each other by a thumb screw 34 having oppositely threaded portions engaging these members, whereby members 33 may be operated to form a spark-gap gauge of variable width. This arrangement of parts presents a three-way positioning unit for the ends 5 of a pair of electrodes l. Contact of the ends 5 with respective sides of gauges 33,

will give a setting for the spark-gap width; contact of said ends 5 with anvils 32 will position them correctly relative to the axis of an atomizer outlet and also the proper distance away from said outlet; hence, a three-way adjustment of the ends 5 may be quickly and accurately obtained, whereupon clamping screws 3 may be tightened, and the adjustment maintained. The element l5 may then be withdrawn and the member I! allowed to retract by the action of the spring l3 to move the gaging elements out of contact with the electrodes. Shaft 8 may then be unscrewed from coupling 1 and replaced by the atomizer 25 whereupon the burner is ready for use, the entire operation requiring only a few minutes time.

Figure 7 represents a device similar to that just described except that the movable plate 35 is operable by a thumb screw 36 for positioning thereof relative to the base member and-is intended for use in factory assembling, or the like, of burner parts, the use of an atomizer for a gauge being dispensed with in this case.

Figures 8, 9 and 10 illustrate another form of device which may be attached directly to the atomizer coupling, or pipe 2. This may be accomplished by providing a clip, member 31, adapted to be received by coupling 1, and arranged to support an L-shaped member, 38, having a stop portion 39 to engage the atomizer end and thereby position said member relative to the atomizer outlet. An electrode-positioning anvil 30, may be carried by member 38 by which the electrodes may easily be positioned relative to the atomizer outlet as in the preceding cases.

This arrangement provides a simple, inexpensive device, which is free from adjustments, and therefore is not universal as in the previous case; however, the principle involved is identical; the anvils 4% being positioned in pre-established relationship with both the exit and the axis of the fuel passageway.

My device is believed to be scientifically accurate, simple to operate and so compact that it may be carried in the pocket. No dismantling of the equipment is required to obtain the electrode setting, merely removal of the atomizer and screwing of shaft 8 into its place, and subsequent placing of the atomizer in the clamped position to be used as a gauge. The only adjustment required of the device is setting element 29 to the scale corresponding to the angle of spray marked on each atomizer, which marking is standard practice today. It will be clear that these scale settings are not arbitrary and variations therefrom are optional with the operator to meet special conditions.

I claim:

1. A device of the class described, comprising a supporting element having means for securing it to a burner in place of the usual nozzle for said burner, a base member carried by said element, a slide carried by said base member, parts on said slide and member, respectively, between which the nozzle of said burner may be engaged to determine a position of said slide relative to said base member, and means carried by said slide for locating when said slide is in said position an electrode properly related to said burner when said device has been removed therefrom and said nozzle replaced in operative position'.

2. A device of the class described, comprising a supporting element, means for securing said element in predetermined position relative to a fuel exitaxis of a burner, a member adjustable relative to said element laterally of said axis and in accordance with the angle of divergence of the fuel issuing from said burner, and means on said member for defining the proper position of an. electrode relative to the burner for the angle of divergence of fuel issuing from said burner for which said, member has been adjusted.

3. A device of the class described, comprising a supporting element, means for securing said element in predetermined position relative to a fuel exit axis of a burner, a member adjustable relative to said element laterally of said axis and in accordance with the angle of divergence of the fuel issuing from said burner, and gaging elements adjustable from and toward each other on said member to determine the proper spacing of a pair of electrodes and the proper positions ofnsaid electrodes for the angle of divergence of the fuel issuing from. said burner for which said member has been adjusted.

4. A device of the class described, comprising a supporting element having means for securing it in predetermined relation to the fuel exit axis of a burner, means adjustably carried by said element both parallel to and transverse ofsaid axis in accordance with the 'point' of issue and the angle of divergence of the fuel from 'said burner, and gaging means carried bysaid adjustable means for determining the proper position of the ends of the ignition electrodes for the position and angle of divergence for which said adjustable means has been set.

5 A device of the class described, comprising an element having means for securing it in definite relation to the fuel axis of a burner, and means carried by said element for locating the proper positions for ignition electrodes for said burner with regard to the angle of divergence of fuel emerging from said burner.

6. A device of the class described, comprising 

